Such tire drums provided with a turn-up mechanism are generally known. They may be designed as tire building drum on which the tire components, in particular liner and carcass layers are supplied and of which a cylindrical casing is being made, and also bead cores are supplied, after which the cylindrical casing on the tire building drum is expanded into a curved torus shape, in which the sides of the casing are turned up about the bead cores by means of the turn-up mechanism. They may also be designed as a curving drum, to which an already formed cylindrical carcass casing has been supplied.
Such a tire building drum including turn-up mechanism is known from British patent specification 1.532.960. When building a tire, portions of the tire components end up on the arms. Because there is room between the arms, and the arms may leave imprints in the portions of the tire components, it has appeared that an accurate tire cannot be manufactured with said known building drum in all cases.